Filmmaker Antoine Fuqua has walked away from a Tupac Shakur biopic to direct a new boxing movie starring Eminem, according to reports.The Training Day director was set to tell the life story of the slain hip-hop hero, who was gunned down and killed in Las Vegas in 1996. However, Fuqua has decided to quit the project to helm Southpaw, which will star the Lose Yourself hitmaker - real name Marshall Mathers - as a left-handed welterweight, according to the Los Angeles Times. Southpaw writer Kurt Sutter explains, "I took meetings with Marshall's producing partners over the past seven years, looking for something to do together. I know he's very selective and doesn't do a lot. But he shared so much of his personal struggle in this raw and very honest album, one that I connected with on a lot of levels... At its core, this (film) is a retelling of his struggles over the last five years of his life, using the boxing analogy."